Development of an electrochemical sensor for heparin utilizing PEDOT:PSS/AuNPs nanocomposites

Heparin is vital in treating thrombotic disorders; it works well as an anticoagulant coating on biomedical devices. Due to its pharmacological nature, excessive heparin can lead to thrombocytopenia, hemorrhage, and hyperkalemia, while too little may cause thrombi. Precise measurement of heparin concentration is essential for clinical practice; therefore, this study developed a heparin sensor utilizing Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate) PEDOT:PSS/gold nanoparticle (AuNPs) nanocomposites. Heparin quantification is achieved via the specific protamine-heparin interaction, with protamine immobilized on the electrode surface. We systematically optimized the deposition conditions of PEDOT:PSS/AuNPs and the concentration of protamine and its incubation time. Following this optimization, the sensor's performance was evaluated using cyclic voltammetry (CV) in a 0.5 mM [Fe(CN)₆] 3−/4- solution over a voltage range spanning from −0.3 V to 0.7 V. The GCE/PEDOT:PSS/AuNPs/PRTM sensor achieved a heparin sensitivity of 8.113 μA·mM −1 ·cm −2 , a low detection limit of 0.05 μM, and a wide linear detection range of 0-35 μM. Under simulated physiological conditions (2.5 % human serum - containing buffer), the system exhibited a linear response to heparin (0–35 μM) and achieved recovery rates of 95.2 %–101.5 %, confirming its anti-interference capability in biological environments. The sensor demonstrated rapid response, high selectivity, wide linear range, and robust reliability, thus enabling its potential as a POCT device for real-time heparin monitoring in blood.